Valve mechanism for engines



No. 623,251. Patented Apr. la, |899. J. T. Lmusmom.

VALVE MEGHANISM FUR ENGINES.

(Application filed Oct. 17, 1898.)

3 Sheets-Sheet iw (No Model.)

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No. 623,25I.

(No Model.)

Patented Apr. I8, |899. J. T. LINDSTRUM.

VALVE MECHANISM FDR ENGINES.

(Application led Oct. 17, 1898.)

3 Shets--Sheet 2.

No. 623,25|. vmmm Apr. la, |899. J. T. LlNnsTRuM.

VALVE MECHANISM FOR ENGINES.

' (Application :Bled Oct. 17, 1898.)

(No Model.) 3 Sheets-Sheet 3.

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UNTTnn STATES PATENT OFFICE,

JOHN T. LIN'DSTROM, OF MOUNT VERNON, OHIO.

VALVE MECHANISM FOR ENGINES.

SPECIFICATION formingpart of Letters Patent No. 623,251, dated April 18,1899.

-Appncanon ined october 17, 1898. serai No. 693,761. on motti.)

This invention relates to valve mechanism' for steam-engines.

The object of the invention is to provide a valve mechanism forsteam-engines which will `loe simple, efficient, and positive inoperation and wherein the use of wrist-plates-and connecting-rods,suchlas are usually employed in steam-engi nes of the Corliss type,isavoided.

Theinvention consists, substantially, in the construction, combination,location, and relative arrangement, all as will be more fullyhereinafter set forth, as shown in the accompanying drawings, andfinally specifically pointed out in the appended claims.

Referring to the accompanying drawings and to the various views andreference-signs appearing` thereon, Figure 1 is aview in side elevation,parts in vertical section, of a type of steam engine showing theapplication thereto of a construction embodying the principles of myinvention. Fig. 2 is a longitudinal sectional view of thesteam-cylinder, showing the arrangement of valves. Fig. is an end viewof the construction shown in Fig. 1, looking to the right of saidligure.

Fig. e is a broken detail view, in longitudinalsection,ofamain-valve-operatingmotor. Fig. 5 is a broken detail view, inside elevation. showing the relative arrangement of cut-off andtripping-cani sleeves for controlling the operation of the mainsupply-valve. Fig. 6 is a broken detail view in plan of the constructionshown in Fig. 5. Fig. 7 is a broken detail view in section on the line 77, Fig. 1, looking in the direction of the arrows. Fig. S is a detacheddetail view of the sleeve for effecting the cut-offof the main valve.Fig. f) is a similar view of the trip-cam sleeve.

The same part is designated by the same reference-sign wherever itoccurs throughout the several views.

Reference-sign A designates the steam-cylinder of an engine; B, the mainengine-shaft; O, the main piston; D E, the main supplyvalves, onearranged at each end of the cylinder, and F G the main exhaustvalves.These parts may be of the usual or any suitable or well-known type,constructiomand arrangement.

In the operation of steam-engines, and particularly engines of theCorliss type, it is usual to provide a rocking or wrist plate andconnect the saine by means of links or connecting-rods with the valvesfor actuating the latter. Such construction and arrangement, however,result in a comparatively7 slow movement of the valves in opening andclosing. This is objectionable for the reason that in order to securethe most efficient operation of the engine the steam-inlet valves shouldbe quickly opened to their fullest extent and as quickly closed, and theexhaust-valve at one end of the cylinder should also be quickly andfully opened immediately upon the opening of the steam-inlet valve atthe other end of the cylinder. These results are not efflciently securedin the constructions employing the wrist-plate and link or rodconnections therefrom to the valves. Moreover, in such construction itis difficult to vary the point of cut-off with Variations of speedwithout the'provision of special and complicated arrangements ofconnections.

It is the special purpose of the present invention to provide aconstruction and arrangement wherein the objections above noted areavoided and wherein the use of a rocking wristl plate and the specialcut-oft' varying connections is avoided and dispensed with.

In carrying out my invention I provide motors for actuating the mainsupply and exhaust valves. Preferably, and as shown, but to which,however, the invention'is not limited or restricted, I providea separatemotor 10 11 12 13 foreach of the main-cylinder valves, the motors 10 and13 serving for the steaminlet valves D E, respectively, andthe motors 11and 12 serving for theexhaust F G. In the particular form shown, towhich, however, theinvention is not limited, these valveoperating motorscomprise cylinders having pistons 14 and rods 15 16 17 1S, respectively,connected to the crank-arms 19 20 21 22 on the stems of theircorresponding valves D E F G. operated by either steam or compressed airor other medium. In practiceI prefer to em- IOO The motors 10, 1l, 12,and 13 may be Utl ploy compressed air. The motor-operating medium issupplied to the motors through thesupply-pipes 23 from any suitable orconveniently-arranged source, the pipes 23 delivering into chambers orcasings 24, having suitable exhaust connections 25, and also connectedto each end of the motorcylinder through pipes or passages 26 27. rl"hepipes Or passages 26 27 deliver in to the motor-cylinder at the extremeends thereof, and arranged in said pipes or passages to seat outwardlyfrom the motor-cylinder ends are the puppetvalves 28 2f). At a pointIadjacent to; but somewhat removed from, the endsof the cylinder passages3031 are provided,opening com m unication between pipes or passages 2G27 and the motorc,vlinders. Arranged in chambers or casings 24 arevalves 32, constructed and arranged to open one end of theiiiotoi--cyliuder to the supply and simultaneously therewith to open theother end of the cylinder io the exhaust. Y

In theoperatiou of the valve mechanism of a steam-engine no specialnecessity exists for varying the point of opening or closing of themain-cylinder exhaust-valves cr for varying the regularity of theirmovements. I will therefore describe the means for controlling thevalves 3;), which govern the motors Il l2, by which the main-cylinderexhaust-valves F G are operated.

Reference'sigu 33 designates a shaft suitably and conveniently arrangedand located and 'journaletil in bearings 34, and from this `shaft thevalves of said motors Il and l2 are actuated. In the particulararrangement shown, to 4which, however, the invention is not limited.shaft 33 is a rocking shaft, and suitable gearing is provided wherebysaid shaft is rocked upon each reciprocation of the main piston. Asillustrative of an operative arrangement I have shown an arrangement foreiecting the rocking movements of shaft 33 wherein an eccentric-rod ispivotally Ycon nected at one end to a cranloartn 36 on said shaft and atthe other end to an eccentric or wrist pin in a disk 37, mounted ou androtating with a shaft 3S, which receives rotation from the maindrive-shaft I3 of the engine through any suitable or convenientarrangement ol' gearing. It is evident, however, that any other suitableor convenient arrangement of gearing may be employed and convenientlyarranged for effecting the rocking movement of shaft 33. From theconstruction shown it will be seen that upon each complete revolut-ionof shaft 3S, and hence of the main drive? shaft B of the engine, theshaft 33 is rocked from one of its limits of movement to the other.Mounted upon shaft 33 and suitably secured to rock therewith are thecrankarms E59 40, respectively connected by links 41,42 to crank-arms 4344 on the stems of valves 32 of the cylinders which actuate and controlthe main exhaust-valves F G. From this construction it will be seen thatthe main exhaustvalves are positively and uniformly acdirection.

tuated upon each rotation of the engine-shaft. By suitably arranging therelative location of the arms 39 40 with reference to lthe direction andextent of rocking movement of shaft 33 it will be seen that theexhaust-valve at one end of the main cylinder may be closed or opened atany desired point in the operation with respect to the opening orclosing of the exhaust-valve at the other end of the cylinder and alsowith respect to the movements of the main piston.

I will no7 describe the arrangement for securing the automaticregulation of the point of cut-off of the main steam-supply valves.

Suitably mounted upon shaft to rock therewith are the sleeves 45, andadjacent to each of said sleeves I arrange the sleeves 47 4S, saidsleeves 47 4S being loosely mounted on said shaft. Pivotally mounted oneach of the sleeves 45 is an arm 49, arranged to project over theadjacent sleeves 47 4S. The sleeve 4S is provided with a cam projection50, having an inclined surface and terminating in an abrupt shoulder 5l.The relativo arrangement of the sleeves 45 and 4S is such that when theshaft is rocked in one direction the pivoted arm 49, carried by sleeve45, will ride up the inclined surface of cam projection 50 until theedge of said projection is cleared, whereupon said arm drops down behindthe abrupt shoulder 5l of said projection and into 'position to engagetherewith upon the reverse rocking movement of shaft 33, thus effectinga coincident and positive rocking movement of said sleeve 4S in the sameIt' desired, a spring 52 may be provided and arranged to act upon arm 49to cause the same to certainly drop down in front of the shoulder 5tassoon as the arm 49 clears the projection 50. The sleeve 4S is providedwith a crank-arm 53, which is pivotally connected through rod 54 to acrank-arm 55 on the stem of valve 32, which controls the motor throughwhich the main steam-supply valves D E are actuated. Thus it will beseen that the valves 32 of themotors which actuate the main steam-supplyvalves are positively moved in one direction. Any suitable means may beprovided for returning the said motor-valve to its initial position. Forinstance, I have shown a spring 5G (see Fig. 4) for accomplishing thisobject. It is obvious, however, that any other equivalent device mayequally well serve the same purpose. The function of sleeve 47 is todisengage the arm 49 from en-' gaging position with respect to theshoulder 5l of cam projection 50, and in order that this disengagementmay be variably effected, according to the speed of the engine, in orderto vary the point of cut-,off of the main steamsupply valve saidsleeve47 is loosely mounted on shaft 33 and is provided in the peripherythereof with a trip-cam 57. The relative arrangement of sleeves 45 and47 is such that during the rocking movements of said sleeve 45 the arm49, carried thereby, will ride over the surface of sleeve 47, and hencein a path IIO enabling the trip-cam 57, carried thereby, t0 engageunderneath said arm and elevate the lsaine above the shouldered cam 50of the cooperating sleeve 4S. In order that the point at which thedisengagement. of arm 40 from cam projection 50 may be varied accordingto the speed of the engine, I provide the sleeves 47 with crank-arms 5Sand connect the same through rods 59 with crank-arms on a rock-shaft GO,suitably and conveniently iournaled. A cran k-arm Gl on said rockshaftisconnected by a rod G2 with one end of a pivoted lever 63. To the otherend of said lever is connected a rod 64, which is attached to thesliding sleeve of the 'governor II. By this arrangement it will beobserved that shaft is rocked more or less, according to the variationsof speed of the governor, and hence of the engine. It will also be seenthat the displacement of sleeves 47 axially or rotarily with referenceto shaft 33 and of sleeves 45 and 48 is thus dependent upon thepositions to which shaft GO is rocked, and hence upon the speed of theengine. In case the engine speeds up beyond the desired point the shaftGO is rocked through its crank-arm connections with the governor, andhence through rods 59 the sleeves 47 are rotarily displaced withreference to sleeves 45 48, so as to bring trip-cam 57 into position totrip arm 4f) from engagement with the shoulder 5l at a point earlier inthe stroke of the main piston. rihe moment the disengagement occurs thespring or equivalent device 56, acting upon the motor-valve 32, returnsthe said valve to its initial position, thus causing the mainsteam-supply valve to cut off. In this manner the cut-off takes place ata point earlier or later in the stroke of the piston, according as thespeed ofthe engine increases or decreases.

A convenient arrangement is shown for actuating the governor H bygearing the same up to shaft 38. It is obvious, however, that thegovernor may be actuated in any other suitable or convenient manner fromany rotating part of the engine.

It is stated above that pipes or passages 26 27 deliver into themotor-cylinders at the respective ends thereof and that outwardlyseatingvalves 2S 2Q are arranged in said pipes or passages. It is also statedthat passages 30 3l serve to open communication between the pipes orpassages 26 27 and the motorcylinder at points adjacent to but somewhatremoved from the ends of the cylinder, the object andpurpose of thisarrangement being to provide means for cushioning the motor-piston i4 atthe ends of its stroke, and thus to prevent pounding of the same againstthe ends of the cylinder. This result and purpose is effected, it willbe observed, by the construction and arrangement above described. IVhenthe piston approaches the end of its stroke, it will close the deliveryend of passage 30 3l at the end of the cylinder toward which the pistonis moving and through which the air, steam, or other medium used on theprevious stroke of the piston is exhausting. The closing of the passage30 3l causes the seating ot' the valve 23 28, and therefore theair-pressure or steam remaining in the cylinder at that end will becompressed, thus cushioning the piston. IVhen, however, the valve 32 isagain actuated to open that end of the cylinder to steam or airpressure,the previously-closed valve 29 opens, thus admitting suchpressure to the cylinder to drive the piston in the opposite direction.

It is obvious that the particular location and arrangement of thevalve-actuating motors and of the shafts 38 33 and 60 are unimportantand may be changed or varied according to the exigencies andrequirements of space and convenience without departure from the spiritand scope of my invention.

4From the foregoing description it will be seen that Iprovide anexceedinglysimple and efficient arrangement of valve-gear forsteamengines wherein the point of cut-off of steamsupply is variedreadily and easily by varia tions in speed, wherein when thesteam-supply valve at one end of the cylinder is opened theexhaust-valve at the other end is immediately opened to its fullestextent, and wherein the movements of the valves are effected positivelyand quickly.

IVhile I have shown and described a specific construction andarrangement of apparatus embodying the principles of my invention, it isobvious that many variations and changes in the details thereof wouldreadily occur to persons skilled in the art and still fall within thespirit and scope of my invenvention. I do not desire, therefore, to belimited or restricted to the exact details shown and described; but,

-I-Iaving set forth the object and vnature ot' my invention and anapparatus embodying the principles thereof, what I claim as new anduseful and of my own invention, and desire to secure by -Letters Patent,is-

l. In a steam-engine, main steam supply and exhaust valves having armsconnected thereto for actuating the same, an' independent motor for eachvalve, each motor comprising a cylinder andpiston,connections betweensaid pistons and valve-arms, and means actuated by variations in speedof the engine for controlling the movements of saidmainsteam-supply-valve-actuating motor-piston, as and for the purposeset forth.

2. In a steam-engine, main steam supply and exhaust valves havingactuating-arms connected therewith, a motor comprising a cylinder andpiston, connections between said piston and the actuating-arm of saidsupplyvalve, an independent motor comprising a cylinder and piston, saidpiston connected to the actuating-arm of said exhaust -valve, meansforcontrolling the supply of operating medium to said motors, and meansfor varying the supply of operating medium to the main steamsupply-valve actuating motor,

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Y nected to said valves for actuating the same,

an independent motor foreach valve, said motors comprising cylinders andpistons, independent connections between the piston of each motor andthe actuating-arm of its corresponding valve, means for controlling thesupply of operating medium to said motorcylinders, a speed-governor andconnections actuated thereby for varying the supply of operating mediumadmitted to the operatingmotor of the main supply-valve, according tothe speed of the engine, as and for the purpose set forth.

et. In a steam-engine, a main cylinder having supply and exhaust valves,an independent compressed-air motor for each valve, connections betweenthe pistonof each motor and the corresponding valve of said maincylinder, a shaft, connections actuated by said shaft for controllingthe supply of compressedair to said motors, and gearing for operatingsaid shaft from the main drive-shaft of the engine, as and-for thepurpose set forth.

5. In a steam-engine, a main cylinder having supply and exhaust valves,a motor for actuating each valve, a rock-shaft, crankarms mountedthereon to rock therewith, connections between said crank-arms and theeX- haust-valve-operating motors for controlling the latter,disconnective devices actuated by said shaft for controlling thesupply-valve- .actuating motors, and means actuated by va- Iriations inthe speed of the engine for varying the point of disconnection of saidcontrolling means, as and for the purpose set forth.

6. In a steam-engine, a main cylinder having a supply-valve, a motor foractuating said valve, a rock-shaft, a sleeve loosely mounted thereon,crank connections between said sleeve and said motor for controlling thelatter, means for detachably coupling said sleeve to rock with saidshaft, and means controlled by the speed of the engine for varying thepoint at which said coupling is released, as and for the purpose setforth.

7. In a steam-engine, a main cylinder having a supply-valve, a motor foractuating said valve, a controlling-valve for said motor, a rock-shaft,a crank-arm loosely sleeved upon said shaft, a rod connecting saidcrank-arm and controlling-valve, a coupling for said sleeve whereby saidsleeve may be coupled to rock with said shaft, and means actuated byvariations in speed of the engine for automatically varying the point ofuncoupling of said sleeve, as and for the purpose set forth.

8. In asteam-engine, a main cylinder having a supply-valve, a motor foractuating said valve, a controllingvalve for said motor, a rock-shaft,acrank-arm loosely sleeved upon said shaft, and connected to saidcontrolling' valve, said sleeved crank provided with a shoulder, apivoted arm sleeved upon said shaft to rock-therewith, said arm arrangedto engage said shoulder, and means for automatically disengaging saidarm from said shoulder, as and for the purpose set forth.

9. In a steam-engine, a main cylinder having a supply-valve, a motor foractuating the saine, a controlling-valve for said motor, a rock-shaft, acrank-arm loosely sleeved upon said shaft and provided with a shoulder,connections between said arm and controllingvalve, a pivoted arm sleevedupon to rock with said shaft, said arm arranged when rocked to engagesaid shoulder and rock said crank-arm in one direction, whereby saidcontrolling-valve is operated in one direction, means for yieldinglyopposing said movement of the controlling-valve, and means forautomatically releasing said pivoted arm from engagement with saidshoulder, as and for the purpose set forth.

l0. In asteam-engine, a main cylinder having a supply-valve, a motor foractuating said Valve, a controlling-valve for said motor, a rock-shaft,a crank-arm having a shoulder and loosely 'sleeved upon said shaft,connections between said crank-arm and controlling-valve, a coupling-armsleeved upon to rock with said shaft and arranged to engage saidshoulder, a tri p-cam for disengaging said arm from-said shoulder, andmeans actuated by variations in speed of the engine for varying thepoint at which said trip-cam operates upon said coupling-arm, as and forthe purpose set forth.

ll. In a steam-engine, a main cylinder having a supply-valve, a motorfor actuating said valve, a rock-shaft, a crank-arm provided with ashoulder and loosely sleeved upon said shaft, aA pivoted arm sleevedupon to rock with said shaft, said arm arranged to engage said shoulder,a sleeve loosely mounted on said shaft and provided with a cam arrangedto disengage said arm from said shoulder, a speedgovernor, andconnections between said governor and loose sleeve whereby the positionof the latter upon said shaft may be rotarily varied according to thespeed of the engine, thereby varying the point of'detachment of saidpivoted arm from said shoulder, as and for the purpose set forth.

In witness whereof I have hereunto set my hand, this 11th day ofOctober, 1898, in the presence of the subscribing witnesses.

JOHN T. LINDSTROM.

Witnesses:

E. C. SEMPLE, S. E. DARBY.

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